Coaxial patchcord assembly



NOV. 8, 1966 MUMMEY ET AL 3,284,755

COAXIAL PATCHCORD ASSEMBLY Filed March 31, 1964 2 Sheets-Sheet 1 INVENTOR5 DA 1.: .Bmcz MUMMi-Y R unm- G-RA TRUMP BYQML. y

Nov. 8, 1966 MUMMEY ET AL 3,284,755

COAXIAL PATCHCORD ASSEMBLY Filed March 31, 1964 2 Sheets-Sheet 2 INVENTORS' JDALE BRICE M Y 'RQBERT Crm-7 BY M m 51-444.

United States Patent Ofitice 3,284,755 COAXIAL PATCHCORD ASSEMBLY Dale Brice Mummey, Enola, and Robert G. Trump,

Hershey, Pa., assignors to AMP Incorporated, Harrisburg, Pa.

Filed Mar. 31, 1964, Ser. No. 356,279 4 Claims. (Cl. 339-128) This invention relates to an improved coaxial terminal device of the type utilized in plugboards.

It is an object of the invention to provide a plugable electrical contactor or terminal for coaxial cable.

It is a further object of the invention to provide a coaxial contactor wherein the inner and outer conductive members are crimped to the inner and outer conductive paths of coaxial cable.

It is another object of the invention to provide a coaxial contactor of the type adapted to be plugged into a board member and to be retained therein against accidental withdrawal by a positive snap action with frictional engagement.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there are shown and described illustrative embodiments of the invention; it is to be understood, however, that these embodiments are not intended to be exhaustive nor limiting of the invention, but are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1 is a side view of the coaxial contactor of the invention inserted in a board member aperture in the position of use;

FIGURE 2 is a perspective of the contactor of the invention somewhat enlarged to show certain aspects thereof;

FIGURE 3 is an exploded perspective of the assembly shown in FIGURE 2;

FIGURE 4 is a longitudinal section of the contactor of the invention included to show the internal aspects including crimps of the various portions of the connector and the relationship of insulating members; and

FIGURE 5 is a section taken along lines 5-5 of FIGURE 4.

Referring now to FIGURE 1, numeral identifies a board member apertured as at 11 to receive the contactor assembly of the invention shown as 30, which effectively terminates a coaxial cable 14. Board member 10 may be a portion of a connector block or may be part of a plugboard assembly having hundreds or thousands of apertures such as 11 into which large numbers of contactors 30 may be inserted to, in elfect, program connections between leads such as 14 and thereby between computer components connected to such leads. The board 10 may be of an insulating material such as phenolic resin, diallyl phthalate or the like, or may be of metal such as aluminum with the apertures 11 molded or drilled therein. One of the requirements for contact-or 30 is that it have a fixed insertion and withdrawal force in an axial sense so as not to become dislodged accidentally from the board aperture. An accidental dislodgement could arise by reason of some force or blow striking the end of the contactor shown as pin 50, or in plugboard use by reason of a plugboard spring member shown dotted in as 51 engaging pin 50. In plugboard use, contactor 30 must be frequently withdrawn from the aperture 11 and reinserted in some other aperture to effec- 3,284,755 Patented Nov. 8, 1966 tively change the program to that desired. As a further requirement, contactor 30 must and should provide a shielding of the center conductive path of cable 14 which is continuous from the cable itself up to and through the board 10.

Contactor 30 accomplishes the above requirements by including an assembly separately terminating the inner and outer conductive paths of cable 14 to spaced and separate conductive paths insulated each from the other by a dielectric material. The assembly components are shown generally as 40, a conductive metallic sleeve forming the outer conductive path and 50, a conductive metallic pin forming the inner conductive path, with 40 and 50 being spaced apart and insulated each from the other by a dielectric insert 34. The rear portion of eon-tactor 30 is surrounded and captivated by an insulating boot 32 made of rubber, lastic or some other insulating material. During insertion and withdrawal, contactor assembly 30 is normally gripped by means of boot 32 to avoid placing undue strains on cable 14. With the construction featured by the invention, however, the connector assembly can, if it is necessary, be withdrawn by pulling upon cable 14 without destroying the connection between the cable conductors and the conductive components of the assembly. In prior art devices wherein the conductive paths of the cable were soldered to the components of the connector, pulling forces applied on cable 14 frequently cracked the solder bond to cause a connection failure. This is avoided in the assembly of the invention in a manner to be hereinafter described.

Referring now to FIGURE 2, the outer conductive path of cable 14 is extended through the assembly 30 by means of the shell or sleeve 40 which is of conductive metallic material having spring characteristics. The rear portion of 40, shown in FIGURES 3 and 4 as 40a, is terminated to a ferrule member 42 which in turn is connected to the outer conductive braid 16 of cable 14 by means to be described. The portion 40a is relieved as at 4011 to provide upon crimping a working of the outside surface of 42 to lock 40 to ferrule 42 with respect to relative rotational movement between the members.

Extending forwardly from portion 40:: is a portion of enlarged diameter shown as 4012 carrying a series of four radially extending dimples 40d which serve to limit the inward travel of the contactor in aperture 11 of board 10. Forward of the dimples 40d, and as an integral part of sleeve 40, is a section 40c having a series of axially extending spring members 40 defined by relieved portions 413i. Each of the spring members 40 has an embossment 4lle struck outwardly to provide a tight frictional spring action which operates to hold assembly 30 within board 10. The preferred length and width of embossments 402 can best be discerned from FIGURES 3-5.

The forward portion of sleeve 40 extends outwardly to an end engaging a flange 34b of an insert 34 of insulating material. Spaced from the dimples 40d by a distance approximately equal to or slightly greater than the thickness of the board in which the assembly is to be used are a series of further dimples 40k similar to 40d which serve to provide a snap action during the insertion of the contactor within the board. Dimples 40k in part serve to hold the contactor against accidental dislodgment. It is preferred that the forward dimples 40k be disposed on the top only and centered in the flange portions as shown, to avoid excessive insertion and withdrawal forces and incident damage to the .board or insert 34. As can be seen, the forward portion of 40 is split in a transverse sense by a slot 401, and in an axial sense by a slot 40m. These slots further serve to prevent excessive insertion and withdrawal forces which might arise if by slight manufacturing tolerance deviation the ends of the portions were to be jammed together to define a diameter larger 3 than the diameter of aperture 11 in board 10. This is particularly true with respect to uses wherein the board is of metal.

As can be seen from FIGURE 4, the sleeve 40 extends well back over the cable 14 and is commoned to a ferrule member 42 which is relatively thick and preferably of a malleable material such as annealed copper. The ferrule 42 has a forward portion 42a which is slightly enlarged to fit within the transition portion of 40 as shown. Ferrule 42 is made to extend over a substantial portion of cable 14 and is crimped inwardly thereagainst over a portion of the cable outer insulating sheath 15 and inwardly against the cable braid 16 against a metallic backing ferrule 44. The backing ferrule 44 is of a harder material to resist crushing of the cable dielectric 18 by the crimp applied to ferrule 42. The braid 16 is then thus terminated to the fer-rule assembly 42 and 44, and thereby to the sleeve 40 to extend the conductive path of the cable along the contactor assembly to the end of 40 proximate 34b as shown in FIGURE 4. The backing ferrule 44 includes a flange 44a which is turned outwardly to define a surface against which the dielectric insert 34 is butted and at the opposite end as at 44b the ferrule is beveled to prevent braid 16 from being cut or separated during the crimping operation. The interior bore of 44 is slightly larger than the maximum diameter of the cable dielectric 18.

In the forward portion "of sleeve 40, as best shown in FIGURES 3 and 4, the dielectric or insulating insert 34 includes a bevelled end 34a adapted to facilitate insertion of the contactor within aperture 11 of board 10. A transverse surface 34b is provided to engage the end of sleeve 40 and hold the members against relative axial movement. Spaced therefrom and underlying the portion 400 of 40 is an annular relief or recess 340 provided in 34 to permit the spring arms 40 to be compressed inwardly upon insertion of the contactor within aperture 11 of board 10 without compressing the insert material. It has been found that combinations of tolerance deviations, as for example an undersized aperture 11 and an oversized contactor assembly 30, can cause contactor failure if the spring arm 40j is forced to work against a solid dielectric 34. The provision of relief by 34c precludes this.

A major portion of 34 includes an inner bore shown as 34a of a diameter to receive the contactor central pin member 50 in a sliding fit. The rear portion of 34 includes a bore 34d of a slightly greater diameter to permit 50 to be inserted in 34 and held against outward axial displacement. Except for the relieved portion 340, insert 34 is in contact and gripped by 40 along its length. At the inner end of 34 proximate the ferrule members is provided a separate dielectric spacer insert 36 which is included to facilitate assembly of the contactor assembly 30 and at the same time positively hold the central contact pin member 50 against accidental engagement with the outer conductive path at ferrule flange 44a.

The center conductive pin member 50 has a forward contact portion 50a and a central portion which is cut away and adapted to be formed as by crimping to mechanically and electrically connect the center conductor 20 of cable 14 to pin 50. The portion 50b is raised upwardly to provide clearance as at 50c and includes flanges 50d folded inwardly as shown in FIGURE 5. On at least one surface of central pin member 50 is a dimple 5012 which extends radially to bite into and engage the material of insert 34 and prevent relative movement in a rotational sense between pin 50 and sleeve 40. Adjacent dimple 50s is an outwardly flared portion 50f which operates by engaging 34d to lock 50 against axial withdrawal from the contactor assembly. The sloped or tapered surface of 50f readily facilitates assembly of the pin within insert 34. Axial displacement of pin 50 to the left relative to the assembly is prevented by the dimple 50c and by the pin engagement with insert 36 which in .URE 3 and is accomplished by first stripping the coaxial cable 14 in the manner indicated from FIGURE 4 and then slipping the member 40, ferrule members 42 and 44, and insert 36 on the cable. Thereafter the pin 50 may be placed on the central conductor 20 and crimped thereto. The ferrule 44 is worked under the braid material and over the dielectric sheath 18 and then the ferrule 42 is brought forward. Thereafter the insert 34 is positioned as indicated in FIGURE 4, being forced down over 50 to but-t against the flange 44a of ferrule 44. During this operation the insert 36 prevents the pin 50 from being jammed in against the ferrule assembly to cause a short between outer and inner conductive paths and as previously mentioned, assures that pin 50 will be properly spaced from the ferrule assembly during use in the presence of axial forces applied to the end of 50 which might tend to work the pin down toward the ferrule assembly. The outer insulating sheath 34 in being worked into the position shown in FIGURE 4 tightly grips the pin member, and through dimple 50c is locked thereto against relative rotational movement. Following this step the sleeve 40 is then applied in a suitable manner as for example by being brought up over the assembly from the \position shown in FIGURE 3. The rear portion of 40a is then crimped inwardly and thereafter a boot such as 32 may be applied by being worked up over the assembly from the position shown in FIGURE 3 to the position shown in FIGURE 4. Alternatively, the boot may be molded on the assembly after the final positioning of assembly 40 and crimping of the ferrules.

In an actual embodiment the center pin member 50 was formed of a stamping of brass sheet material approximately twelve tho-usandths of an inch in thickness overplated with a layer of nickel and gold to provide desirable electrical characteristics and to resist corrosion of the parts. The other sleeve 40 was formed of spring grade brass, nickel plated and approximately of ten thousandths of an inch in thickness. The ferrules 42 and 44 were of leaded copper in the annealed condition and gilding copper, respectively; the ferrule 42 being of fifty thousandths of an inch in thickness. The dielectric insert 34 and the insulating bead 36 were of polyethylene material and the relief 34c was approximately seven thousandths of an inch.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1. A plug contactor for terminating coaxial cable of the type having a center conductor surrounded by an insulating member and an outer conductor, the contactor including a metallic shell member of a diameter to be inserted within the aperture of a contactor board member, the said shell member having a plurality of integral spring members of a length approximating the thickness of the board member disposed generally parallel to the longitudinal axis of said contactor and positioned radially outward-1y from the main body of said shell member such as to be driven inwardly by insertion in the board memher aperture to frictionally engage said board aperture substantially along the length thereof, stop means located on said shell extending radially to limit the insertion of said contactor in said board member, ferrule means disposed in the rearward end of said shell and connected to the outer conductor of said cable, an insulating medium disposed within said shell extending approximately from said ferrule means to the forward end of said shell, a central conductive pin member connected to the cable center conductor and supported by said insulating medium coaxially of a portion of the length of said shell, said pin member extending forwardly of said insulating medium and said shell, the said insulating medium including a portion disposed between the inner end of said pin member and said ferrule means to preclude axial displacement of said pin member toward said ferrule means during assembly and use of said contactor.

2. The contactor of claim 1 wherein said portion of said insulating medium is formed by a sleeve having an inner diameter slightly larger than the center conductor of said cable and an outer diameter at least equal to that of said center pin member.

3. The contactor of claim 1 wherein said shell member is split along its length to provide a generally C-shape-d cross section and the said ferrule means and insulating medium each include portions having a circumference slightly greater than the circumference of the interior surface of said shell member whereby said shell member is fitted over said ferrule means and insulating medium with a spring act-ion operable to hold said shell member on said ferrule means and insulating medium.

4. The contactor of claim 1 wherein the said shell member is split along at least the forward .portion of the contactor and is of a circumferential length slightly less than that of said insulating medium at the same relative position to permit deformation of said shell member inwardly upon insertion of said contactor within said board aperture and there is provided a relieved portion proximate the end of said shell member defining a flange adapted for movement inwardly in a spring action, radial extensions extending from said flange outwardly to provide a snap action upon insertion of said contaotor through the aperture of said board member. 

1. A PLUG CONTACTOR FOR TERMINATING COAXIAL CABLE OF THE TYPE HAVING A CENTER CONDUCTOR SURROUNDED BY AN INSULATING MEMBER AND AN OUTER CONDUCTOR, THE CONTACTOR INCLUDING A METALLIC SHELL MEMBER OF A DIAMETER TO BE INSERTED WITHIN THE APERTURE OF A CONTACTOR BOARD MEMBER, THE SAID SHELL MEMBER HAVING A PLURALITY OF INTEGRAL SPRING MEMBERS OF A LENGTH APPROXIMATING THE THICKNESS OF THE BOARD MEMBER DISPOSED GENERALLY PARALLEL TO THE LONGITUDINAL AXIS OF SAID CONTACTOR AND POSITIONED RADIALLY OUTWARDLY FROM THE MAIN BODY OF SAID SHELL MEMBER SUCH AS TO BE DRIVEN INWARDLY BY INSERTION IN THE BOARD MEMBER APERTURE TO FRICTIONALLY ENGAGE SAID BOARD APERTURE SUBSTANTIALLY ALONG THE LENGTH THEREOF, STOP MEANS LOCATED ON SAID SHELL EXTENDING RADIALLY TO LIMIT THE INSERTION OF SAID CONTACTOR IN SAID BOARD MEMBER, FERRULE MEANS DISPOSED IN THE REARWARD END OF SAID SHELL AND CONNECTED TO THE OUTER CONDUCTOR OF SAID CABLE, AN INSULATING MEDIUM DISPOSED WITHIN SAID SHELL EXTENDING APPROXIMATELY FROM SAID FERRULE MEANS TO THE FORWARD END OF SAID SHELL, A CENTRAL CONDUCTIVE PIN MEMBER CONNECTED TO THE CABLE CENTER CONDUCTOR AND SUPPORTED BY SAID INSULATING MEDIUM COAXIALLY OF A PORTION OF THE LENGTH OF SAID SHELL, SAID PIN MEMBER EXTENDING FORWARDLY OF SAID INSULATING MEDIUM AND SAID SHELL, THE SAID INSULATING MEDIUM INCLUDING A PORTION DISPOSED BETWEEN THE INNER END OF SAID PIN MEMBER AND SAID FERRULE MEANS TO PRECLUDE AXIAL DISPLACEMENT OF SAID PIN MEMBER TOWARD SAID FERRULE MEANS DURING ASSEMBLY AND USE OF SAID CONTACTOR. 